A new issue of this journal has just been published. To see abstracts of the papers it contains (with links through to the full papers) click here:
See selected papers from this issue here:
H, C, N and S stable isotopes and mineral profiles to objectively guarantee the authenticity of grated hard cheeses
02 November 2011, 21:32:23
Publication year: 2011
Source: Analytica Chimica Acta, Available online 2 November 2011
Federica Camin, Ron Wehrens, Daniela Bertoldi, Luana Bontempo, Luca Ziller, ...
In compliance with the European law (EC N. 510/2006), geographical indications and designations of origin for agricultural products and foodstuffs must be protected against mislabelling. This is particularly important for PDO hard cheeses, as Parmigiano Reggiano, that can cost up to the double of the no-PDO competitors.This paper presents two statistical models, based on isotopic and elemental composition, able to trace the origin of cheese also in grated and shredded forms, for which it is not possible to check the logo fire-marked on the rind. One model is able to predict the origin of seven types of European hard cheeses (in a validation step, 236 samples out of 240 are correctly recognised) and the other specifically to discriminate the PDO Parmigiano Reggiano cheese from 9 European and 2 extra-European imitators (260 out of 264 correct classifications). Both models are based on Random Forests. The most significant variables for cheese traceability common in both models are δC, δH, δN, δS and Sr, Cu, Mo, Re, Na, U, Bi, Ni, Fe, Mn, Ga, Se, and Li. These variables are linked not only to geography, but also to cow diet and cheese making processes.
Source: Analytica Chimica Acta, Available online 2 November 2011
Federica Camin, Ron Wehrens, Daniela Bertoldi, Luana Bontempo, Luca Ziller, ...
In compliance with the European law (EC N. 510/2006), geographical indications and designations of origin for agricultural products and foodstuffs must be protected against mislabelling. This is particularly important for PDO hard cheeses, as Parmigiano Reggiano, that can cost up to the double of the no-PDO competitors.This paper presents two statistical models, based on isotopic and elemental composition, able to trace the origin of cheese also in grated and shredded forms, for which it is not possible to check the logo fire-marked on the rind. One model is able to predict the origin of seven types of European hard cheeses (in a validation step, 236 samples out of 240 are correctly recognised) and the other specifically to discriminate the PDO Parmigiano Reggiano cheese from 9 European and 2 extra-European imitators (260 out of 264 correct classifications). Both models are based on Random Forests. The most significant variables for cheese traceability common in both models are δC, δH, δN, δS and Sr, Cu, Mo, Re, Na, U, Bi, Ni, Fe, Mn, Ga, Se, and Li. These variables are linked not only to geography, but also to cow diet and cheese making processes.
Graphical abstract available
. Random Forest Model based on δC, δH, δN, δS and the content of Sr, Cu, Mo, Re, Na, U, Bi, Ni, Fe, Mn, Ga, Se, Er, Dy, Pb, Li, usable for the protection of PDO Parmigiano Reggiano cheese from mislabelling. The correct classification rate in cross-validation is 98.6%.
Highlights► The isotopic and elemental profile of over 260 hard cheese samples are discussed. ► Two validated and immediately applicable statistical models are presented. ► One model is able to predict the origin of seven types of European hard cheeses. ► The other one allows to discriminate the PDO Parmigiano Reggiano cheese from imitators. ► The most significant variables are δC, δH, δN, δS and the content of 16 elements.
Detection of singly- and doubly-charged quaternary ammonium drugs in equine urine by liquid chromatography-tandem mass spectrometry
02 November 2011, 21:32:23
Publication year: 2011
Source: Analytica Chimica Acta, Available online 2 November 2011
Emmie N.M. Ho, W.H. Kwok, April S.Y. Wong, Terence S.M. Wan
Quaternary ammonium drugs (QADs) are anticholinergic agents some of which are known to have been abused or misused in equine sports. A recent review of literature shows that the screening methods reported thus far for QADs mainly cover singly-charged QADs. Doubly-charged QADs are extremely polar substances which are difficult to be extracted and poorly retained on reversed-phase columns. It would be ideal if a comprehensive method can be developed which can detect both singly- and doubly-charged QADs. This paper describes an efficient liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the simultaneous detection and confirmation of 38 singly- and doubly-charged QADs at sub-ppb to low-ppb levels in equine urine after solid-phase extraction.Quaternary ammonium drugs were extracted from equine urine by solid-phase extraction (SPE) using an ISOLUTECBA SPE column and analysed by LC/MS/MS in the positive electrospray ionisation mode. Separation of the thirty-eight QADs was achieved on a polar group embedded C18 LC column with a mixture of aqueous ammonium formate (pH 3.0, 10 mM) and acetonitrile as the mobile phase. Detection and confirmation of the 38 QADs at sub-ppb to low-ppb levels in equine urine could be achieved within 16 min using selected reaction monitoring (SRM). Matrix interference of the target transitions at the expected retention times was not observed. Other method validation data, including precision and recovery, were acceptable. The method was successfully applied to the analyses of drug-administration samples.
Source: Analytica Chimica Acta, Available online 2 November 2011
Emmie N.M. Ho, W.H. Kwok, April S.Y. Wong, Terence S.M. Wan
Quaternary ammonium drugs (QADs) are anticholinergic agents some of which are known to have been abused or misused in equine sports. A recent review of literature shows that the screening methods reported thus far for QADs mainly cover singly-charged QADs. Doubly-charged QADs are extremely polar substances which are difficult to be extracted and poorly retained on reversed-phase columns. It would be ideal if a comprehensive method can be developed which can detect both singly- and doubly-charged QADs. This paper describes an efficient liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the simultaneous detection and confirmation of 38 singly- and doubly-charged QADs at sub-ppb to low-ppb levels in equine urine after solid-phase extraction.Quaternary ammonium drugs were extracted from equine urine by solid-phase extraction (SPE) using an ISOLUTECBA SPE column and analysed by LC/MS/MS in the positive electrospray ionisation mode. Separation of the thirty-eight QADs was achieved on a polar group embedded C18 LC column with a mixture of aqueous ammonium formate (pH 3.0, 10 mM) and acetonitrile as the mobile phase. Detection and confirmation of the 38 QADs at sub-ppb to low-ppb levels in equine urine could be achieved within 16 min using selected reaction monitoring (SRM). Matrix interference of the target transitions at the expected retention times was not observed. Other method validation data, including precision and recovery, were acceptable. The method was successfully applied to the analyses of drug-administration samples.
Graphical abstract available
Highlights► A high throughput screening method for 38 singly- and doubly-charged QADs. ► QADs are difficult to be extracted and poorly retained on reversed-phase columns. ► Separation of QADs using polar group embedded C18 LC column. ► Easily expandable to accommodate more target analytes.Lanthanides determination in red wine using ultrasound assisted extraction, flow injection, aerosol desolvation and ICP-MS
29 October 2011, 21:16:34
Publication year: 2011
Source: Analytica Chimica Acta, Available online 29 October 2011
Fabrina R.S. Bentlin, Clarissa M.M. dos Santos, Érico M.M. Flores, Dirce Pozebon
This paper deals with the determination of the fourteen naturally occurring elements of the lanthanide series in red wine. Ultrasound (US) was used for sample preparation prior lanthanides determination using ICP-MS. Flow injection (FI) and pneumatic nebulization/aerosol desolvation were used for nebulization of aliquots of 50 μL of sample and its subsequent transportation to plasma. Sample preparation procedures, matrix interference and time of sonication were evaluated. Better results for lanthanides in red wine were obtained by sonication with US probe for 90 s and sample 10-fold diluted. The limits of detection of La, Ce, Nd, Sm, Gd, Pr, Eu, Tb, Dy, Ho, Er, Tm, Lu and Yb were 6.57; 10.8; 9.97; 9.38; 2.71; 1.29; 1.22; 0.52; 2.35; 0.96; 2.30; 0.45; 0.24 and 1.35 ng L, respectively. Red wines of different varieties from three countries of South America were discriminated according to the country of origin by means of multivariate analysis of lanthanides concentration.
Source: Analytica Chimica Acta, Available online 29 October 2011
Fabrina R.S. Bentlin, Clarissa M.M. dos Santos, Érico M.M. Flores, Dirce Pozebon
This paper deals with the determination of the fourteen naturally occurring elements of the lanthanide series in red wine. Ultrasound (US) was used for sample preparation prior lanthanides determination using ICP-MS. Flow injection (FI) and pneumatic nebulization/aerosol desolvation were used for nebulization of aliquots of 50 μL of sample and its subsequent transportation to plasma. Sample preparation procedures, matrix interference and time of sonication were evaluated. Better results for lanthanides in red wine were obtained by sonication with US probe for 90 s and sample 10-fold diluted. The limits of detection of La, Ce, Nd, Sm, Gd, Pr, Eu, Tb, Dy, Ho, Er, Tm, Lu and Yb were 6.57; 10.8; 9.97; 9.38; 2.71; 1.29; 1.22; 0.52; 2.35; 0.96; 2.30; 0.45; 0.24 and 1.35 ng L, respectively. Red wines of different varieties from three countries of South America were discriminated according to the country of origin by means of multivariate analysis of lanthanides concentration.
No comments:
Post a Comment